Animal behaviour has been one of the fastest-growing scientific disciplines of recent years. Its impact on the way we think about biology has spawned lucid 'best sellers' like The Selfish Gene and widespread scientific and public debate about our view of the natural world and our place in it. This book provides a comprehensive introduction to the study of behaviour, from its basis in the animal's anatomy and physiology to its adaptive value in the environment. It is aimed at undergraduate students in the biological sciences and psychology and is designed to serve as both a detailed introduction and an extensive, up-to-date source of reference enabling students to pursue topics in the primary literature.